The primary goal of this continuing project is to describe the metabolism of chondroitin SO4 in chick embryo tissues. In the coming year the work will deal with (1) the glycosyl and sulfuryl transferases involved in chondroitin SO4 biosynthesis, (2) the properties and cellular levels of the catabolic enzymes which degrade chondroitin SO4, (3) the pathway of proteochondroitin SO4 biosynthesis and secretion, including the intracellular sites of the different steps in the pathway and the effects inhibitors in interruption of the sequence in monolayer chondrocyte cultures, and (4) the cellular events involved in the release of matrix vesicles into the culture medium of chondrocyte monolayers.